The CP-140 Aurora is very similar externally to the Lockheed P-3C Orion (Canadian ESM wingtip pods instead of the American ESM wing pod), but is different internally, using two sets of mission systems that were first installed in yet another Lockheed anti-submarine warfare aircraft, the carrier-based S-3A Viking. The aircraft's sensors are primarily intended for anti-submarine warfare (ASW) work but are also capable of maritime surveillance, counter-drug and search-and-rescue missions. The CP-140 is Canada's only strategic Intelligence Surveillance and Reconnaissance (ISR) aircraft, conducting long range missions over land, water and littoral areas. These missions are flown in support of Canadian Joint Operations Command, the RCMP, and several other federal government departments.

In 1991, Lockheed shut down its production lines in Burbank, California for the P-3 Orion, which shares the same airframe with the CP-140. Three surplus airframes on hand were purchased by the Air Command, but delivered without the anti-submarine fit. These three aircraft were designated the CP-140A Arcturus and are used primarily for pilot training and coastal surface patrol missions.[2]

The Aurora Incremental Modernization Project (AIMP), initiated in 1998 to upgrade electronics of the Aurora fleet was halted by the government on 20 September 2007 to evaluate whether the aging fleet should continue to be upgraded or replaced by more modern aircraft.[3] On 18 December 2007 the Department of National Defence rescinded this work suspension so that the project could continue. Work includes upgrading computer, navigation, communication and radar systems as well as making structural improvements to ten of eighteen aircraft. The intent of the modernization project is to "keep the aircraft safe and operationally viable until 2020.".[4]

AIMP is currently divided into three 'blocks". Block I is complete and concentrated on the replacement of unsupportable systems. Block II is now completed and brought a glass cockpit with the Navigation and Flight Instruments (NFI) component provided by CMC Electronics,[5] and a complete replacement of the communications suite. Block III is a wholesale replacement of the aircraft's sensors and mission computer.

The Aurora Structural Life Extension Project (ASLEP) is proceeding with 10 of the 18 Auroras scheduled to receive new wings and the replacement of key structural components. The complete ASLEP solution replaces the aircraft's outer wings, center wing lower section and horizontal stabilizers with new production components. All fatigue-life limiting structures on the aircraft are replaced with enhanced-design components and improved corrosion-resistant materials that will greatly reduce maintenance costs over the aircraft's service life. This program is expected to extend the CP140s' service life by 15,000 flight hours per airframe.[6]

The Aurora was acquired in the early 1980s to replace the CP-107 Argus and to further support Canada's anti-submarine warfare mission obligations under NATO for the northwest Atlantic sector.[7] Short deployments to Alaska (Adak), Hawaii (Kaneohe Bay), Iceland (Keflavik), the UK (St Mawgan and Kinloss), and Norway (Andoya) were the norm. However, since the end of the Cold War, they had been used primarily in coastal surveillance and sovereignty patrols by providing an all-weather mission surveillance platform. Increasingly as the CP-140 moves into the 21st century it is employed for domestic and international surveillance by CANCOM for security, counter-terrorism and smuggling, as well as to monitor foreign fishing fleets off Canada's coasts. CP-140s have also been deployed on operations such as Operation Assistance, Operation Apollo and Operation Impact.

Deployments have included OP SHARPGUARD (Yugoslavia blockade), OP SIRIUS (Mediterranean Patrols), OP APOLLO (Persian Gulf region), and counter-narcotics patrols in the Gulf of Mexico and Pacific.[8] Through all this, patrols of the Canadian Arctic continue to take advantage of the airframe's unique abilities.[9]

Lacking the expensive, heavy and sensitive anti-submarine warfare as well as the anti-surface warfare fittings of the CP-140 Aurora, the Arcturus was more fuel efficient and was used for crew training duties (such as touch-and-go landing practice), general maritime surface reconnaissance (detecting drug operations, smuggling of illegal immigrants, fisheries protection patrols, pollution monitoring, etc.), search-and-rescue assistance and Arctic sovereignty patrols. The Arcturus did possess a superior AN/APS-507 surface search radar, incorporating modern functions such as track-while-scan that the Aurora's AN/APS-506 radar lacks but the Arcturus did not have an integrated mission computer, or mission systems. It did, however, maintain the same military communications suite as the CP-140 Aurora.[citation needed]

All three aircraft were based at 14 Wing, one was used for technician training with the school on base CFB Greenwood, Nova Scotia. Two of the CP-140As were retired in 2011 when they were delivered to the Aerospace Maintenance and Regeneration Group (AMARG) in Tucson, Arizona.[11]